The solid solution or bead technique is well-known in the cement industry and in the iron and steel industry.
Crucibles employed for fusion are known for example from European Patent Application no. 0,042,327 filed by IRSID, in which a platinum crucible and a vitreous carbon crucible are described; the induction furnace for the automatic preparation of beads from a mixture of the sample and flux is also known, for example from French Patent Application published under no. 2,381,303 and its Certificate of Addition no. 2,428,834, also in the name of IRSID.
"Bead-preparation" machines and "spectrometers" are also well-known and are commercially available, for example from the Applicant under the designations "PERL'X-2" and "PW 1600/10".
Until recently the sample-and-flux mixture was dosed manually by means of a known electronic sample-mixture balance and the transfer of the mixture into a crucible and the transfer of the bead into the spectrometer were also effected manually; however, the current trend is to automate the various operations to a maximum extent, in particular in the cement industry, as revealed in French Patent Application no. 2,485,733.
This last-mentioned Application describes an automatic sample-preparation device; and this device comprises a weighing machine which consecutively receives the sample and the flux material, and a manipulator arm for consecutively transferring the crucibles from the weighing machine to the induction furnace.
This gives rise to problems because the sample is "stickier" than the flux so that it tends to stick to the receptacle walls and also because the crucibles are very expensive so that the crucible "chain" is an expensive solution.